Design: The output of the `info` subcommand ought to be directly
consumable in a format like JSON or yaml.
The structure being a map of sorts.
Each subsection of information being an individual cluster under the
top-level, like platform info, debug, storage, etc.
Even if there are errors under the top level key, the value will be a
map with the key of "error" and the value as the message of the
`err.Error()`. In this way, the command always returns usable output.
Ideally there will be a means for anything that can register info to do
so independently from it being in the single info.go, so this approach
is having a typed signature for the function that gives info, but i'm
sure it could be better.
Current iteration of this outputs the following as a limited user:
```yaml
host:
MemFree: 711307264
MemTotal: 2096222208
SwapFree: 2147479552
SwapTotal: 2147479552
arch: amd64
cpus: 1
os: linux
store:
error: 'mkdir /var/run/containers/storage: permission denied'
```
and as root (`sudo kpod info -D`):
```yaml
debug:
compiler: gc
go version: go1.7.6
goroutines: 3
host:
MemFree: 717795328
MemTotal: 2096222208
SwapFree: 2147479552
SwapTotal: 2147479552
arch: amd64
cpus: 1
os: linux
store:
ContainerStore:
number: 1
GraphDriverName: overlay2
GraphRoot: /var/lib/containers/storage
ImageStore:
number: 1
```
And with the `--json --debug` flag:
```json
{
"debug": {
"compiler": "gc",
"go version": "go1.7.6",
"goroutines": 3
},
"host": {
"MemFree": 709402624,
"MemTotal": 2096222208,
"SwapFree": 2147479552,
"SwapTotal": 2147479552,
"arch": "amd64",
"cpus": 1,
"os": "linux"
},
"store": {
"ContainerStore": {
"number": 1
},
"GraphDriverName": "overlay2",
"GraphRoot": "/var/lib/containers/storage",
"ImageStore": {
"number": 1
}
}
}
```
Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>